AudioLiquid Converter User Guide

Transcription

1 AudioLiquid Converter User Guide Acon Digital Media GmbH

2 AudioLiquid Converter User Guide All rights reserved. No parts of this work may be reproduced in any form or by any means - graphic, electronic, or mechanical, including photocopying, recording, taping, or information storage and retrieval systems - without the written permission of the publisher. Products that are referred to in this document may be either trademarks and/or registered trademarks of the respective owners. The publisher and the author make no claim to these trademarks. While every precaution has been taken in the preparation of this document, the publisher and the author assume no responsibility for errors or omissions, or for damages resulting from the use of information contained in this document or from the use of programs and source code that may accompany it. In no event shall the publisher and the author be liable for any loss of profit or any other commercial damage caused or alleged to have been caused directly or indirectly by this document.

3 Table of Contents I Table of Contents 3 Part I Introduction 1 Requirements Part II Using the Batch Processor 1 Adding Source Files... 4 Importing Folders... Importing Audio Tracks... from CDs Creating Folders... Removing an Item The Target Files Page... 7 Adding Processing Tools... 8 Defining File and Sample... Format 9 Specifying the Target... Folder 9 Part III Audio Processing 9 1 Adjusting the Volume The Channel Mixer Dynamic Processor Limiter Equalizer High Frequency... Rebirth 15 7 Stereo Enhancer Using Audio Plug-Ins Refreshing the Plug-in... List 17 Specifying VST Directories Part IV Creating Audio CDs 18 1 Adding an Existing... Audio File 19 2 Burning the CD Part V Concepts of Digital Audio 20 1 Sampling Quantization The Decibel Unit... (db) 21 Part VI Preferences and Device Settings 21 1 Device Settings... 21

4 II AudioLiquid Converter User Guide 22 Index

5 Introduction 1 3 Introduction AudioLiquid Converter helps you process and convert file or sample formats of multiple files or complete folder structures with a minimum of mouse clicks. The integrated processing tools include volume and dynamic processing, stereo field editing and equalizing. You can extend the range of processing tools with third party VST or DirectX compatible plug-ins. Audio tracks from CDs are easily imported using the integrated CD ripping tool and the integrated CD burner lets you create audio CDs from audio files. When ripping audio tracks from CDs you can automatically look up artist and title information from the internet using the FreeDB internet database. 1.1 Requirements Before you install AudioLiquid Converter, please make sure your computer fulfills the following requirements: A Pentium III or compatible processor Minimum 256 MB RAM In addition, you will need the following software installed on your computer: Windows XP or Windows Vista DirectX 8.0 or later 2 Using the Batch Processor AudioLiquid Converter allows you to convert and processed a large number of files without user interaction. Even complete directory structures can be processed at once. A new batch processing window is opened automatically when you start AudioLiquid Converter. To open a new batch processing window, select File New Batch Processing Window..., and a the batch processing window appears on your screen as depicted below.

6 4 AudioLiquid Converter User Guide The batch processing window window. 2.1 Adding Source Files The first step of the batch processor window is to add the source files. The most straight forward way to add files is to click the button labelled "Add files". A standard file open dialog opens where you can browse and choose one or more files to open. You can repeat this procedure if you wish to add files from several folders. The source files can be arranged in folders or you can choose to import complete folder structures. Note You can listen to the imported files by clicking the preview button below the file list. Click the stop button to stop previewing. Importing Folders To import the complete content of a folder, click the button labelled "Add folder". The following dialog box appears:

7 Using the Batch Processor The import folder dialog box allows you to import complete folder structures. Use the folder browser to select the folder you wish to import. You can choose to import only the content of the selected folder or the whole folder structure by clicking the check box "Include subdirectories". The "Import files of type" drop down list lets you reduce the files to all known file formats or a specific file format only Importing Audio Tracks from CDs It is possible to digitally import audio data from audio CDs with most CD-ROM readers. AudioLiquid Converter will import title and artist information if available as CD-TEXT. If no CD-TEXT is available, you can perform an internet look-up in the FreeDB data base. To import one or more audio tracks: 1. Click the CD Import button in the source page of the batch processing window. If the CD doesn't contain any CD-TEXT information, you will be asked if you want AudioLiquid Converter to look for artist and title information in the FreeDB data base on the Internet. If you choose no, the CD Track Extraction dialog box appears 5

8 6 AudioLiquid Converter User Guide immediately. If you choose yes, there might be several entries matching your CD. Please choose the correct album from the list and choose OK. 2. If you have several CD-ROM devices installed, please make sure that the device that contains your source audio CD is selected in the CD-ROM Device drop-down list. 3. Select the track or the tracks you wish to import from the track list. 4. Click the button labelled Extract. The CD Track Extraction dialog box The imported audio tracks appear as ordinary file items in the source page of the batch processing window. Adding Track Titles and Album Information Manually If there is no FreeDB entry available for your CD you want to modify the information, you can do this manually in the CD Track Extraction dialog. To rename a track title, double click the track entry in the list or press F2. A dialog box appears where you can enter the new track name.

9 Using the Batch Processor 7 The album information can be changed directly with the edit boxes in the Album Information group box. Note You can listen to the content of a track by clicking the button labelled Preview Creating Folders You can also create target folder structures manually by clicking the "Create folder" button. A dialog box appears where you can enter the name of the new folder Removing an Item You can remove an item (file or folder) by selecting the item and clicking the button labelled "Remove item". 2.2 The Target Files Page When you have added all the files you wish to convert or process you can proceed to the "Target Files" page by clicking the "Next" button or the "Target Files" tab. The following page appaers: The Target Files page of the batch processing window.

10 8 AudioLiquid Converter User Guide Note You can choose to start processing from the Target Files page any time by clicking the button labelled "Start" below the Target Files page. Adding Processing Tools AudioLiquid Converter lets you process the files with internal tools and effects as well as VST and DirectX plug-ins. The "Processing Tools & Effects" section of the Target Files page contains a list of the processing tools that are to be used when processing the files. To add a processing tool, click the button labelled "Add". The "Processing Tools Browser" appears from which you can select the effect, processing tool or plug-in you wish to add to the list. The Processing Tools Browser lets you select an internal processing tool or a plug-in. When you have selected the processing tool, click the button labelled "Add". You can change the parameter settings of a processing tool by clicking the "Edit" button or by double clicking an item in the Processing Tools & Effects list. To remove a processing tool from the list, click the processing tool to highlight it and click the "Remove" button. Loading Effect Chain Files

11 Using the Batch Processor AudioLiquid Converter is able to import complete effect chains created by the effect chainer in the Acoustica audio editor or the free EffectChainer from Acon Digital Media. To load an effect chain file, click the "Load chain" button. A standard file open dialog box appears where you can select the effect chain file you wish to load Defining File and Sample Format The "File & Sample Format" section of the Target Files page lets you select an output file format. To set the output file format you can simply choose the output format from the file type drop-down list. If the file format offers custom parameters settings, like encoding bitrate for mp3 files, you can edit theese settings by clicking the button labelled "Options" next to the file type drop-down list. Furthermore, you can define the sample rate, number of channels and resolution of the target files. If you convert high resolution audio files to a lower resolution, you can optionally apply dithering and noise shaping Specifying the Target Folder The last section of the Target Files page lets you select an output folder. You can either enter a folder path in the edit box or click the button labelled "Browse" to select a folder from the folder structure of your computer. 3 Audio Processing In AudioLiquid Converter, all the processing tools have some properties in common. The processing is performed on the selected region and the selected channels only. Furthermore, most tools offer a preset manager that allows you to save often used parameter settings for later use. The Preset Manager found in most of the processing tools in AudioLiquid Converter To add a preset: Click the button labelled More... A drop down menu appears. Select Add Preset... from the menu. In the pop-up dialog, enter the name of the preset and click the button labelled OK. Loading a preset is equally simple. Just select the preset from the drop-down list and the preset settings are loaded. User presets can be removed by clicking the button labelled More..., selecting Remove Preset... and selecting the preset you wish to remove. 9

12 10 AudioLiquid Converter User Guide You can bypass the effect processing by checking the check box labelled Bypass transform for a convenient A / B comparison. The processing tools introduce some custom controls that you should get familiar with. The level slider is similar to the Windows track bar, but with some enhancements. The value range and the current value is always displayed. You can manually edit the value by pressing the space bar when the control is active or by clicking the value text below the level slider. An edit box pops up containing the current value. To change the value, enter a new value and press return. By pressing the Esc key the changes are discarded. Examples of knobs (1) and level sliders (2). The knob control is similar to the level slider, but it is round and is often used to save space in complex layouts. As with the level sliders, you can change the value by pressing the space bar or by clicking the value text below the knob. A more complex custom control is the curve control which is used when a curve input is needed. The curve control allows the user to add, move or remove points. Straight lines between the points build the curve. You can add points by clicking the location where you want a new point to appear in the curve control. You can remove points by clicking the right mouse button over an existing point. Examples of a curve edit control.

13 Audio Processing Adjusting the Volume The most basic volume manipulation tool is the Adjust Volume tool. The only parameter is the volume change in decibel. For more information on the decibel unit, see The Decibel Unit (db). The Adjust Volume settings 3.2 The Channel Mixer The Channel Mixer is a tool that allows mix input channels for each output channel. With this tool you have complete control over the stereo field of stereo recordings or the surround field of multichannel recordings. The channel mixer mixes the content of the input channels with a user defined levels for each output channel. You can select the output channel using the tabs and adjust the level of each input channel in the mix using the level sliders. The Channel Mixer settings

14 12 AudioLiquid Converter User Guide 3.3 Dynamic Processor A dynamic processor is used to alter the dynamic properties of the recording. To understand how a dynamic processor works, imagine a sound engineer trying to maintain an as steady volume level as possible while doing a recording. When the input level increases he pulls down the volume slider, and he pulls it up when the input level decreases. A dynamic processor does the same thing automatically, only with a much faster reaction time. The Dynamic Processor settings Settings An editable curve containing the output level as a function of the input level. By altering this curve you can change the dynamic characteristics of the recording to fit your needs. Attack time

15 Audio Processing 13 The reaction time when the input level of the source material increases. Release time The reaction time when the input level of the source material decreases. 3.4 Limiter Limiters belong to the dynamic processing tools and ensure that the signal level doesn't exceed a user selectable boundary while minimizing any possible distortions. To achieve this, limiters introduce a certain latency, called look-ahead. The look-ahead ensures that the limiter can respond in time when the signal level suddenly rises. Many CD producers also use limiters to push the perceived volume to a maximum without introducing audible distortions. The Limiter settings Settings Threshold All signals above the threshold level will be attenuated so that the threshold level is not exceeded. Output Gain The output gain of the limiter which corresponds to the highest possible output signal level. Release time knob You can use the release time knob to adjust the response time when the input level of the source material decreases. Longer release times will result in a smoother sound.

16 14 AudioLiquid Converter User Guide Look ahead knob You can adjust the number of milliseconds the limiter uses to determine its internal gain settings with the look-ahead knob. The limiter will have a latency equal to the look ahead time. 3.5 Equalizer AudioLiquid Converter features a powerful six band parametric equalizer. Unlike a graphic equalizer, a parametric equalizer allows the user to select the center frequency of the bands. The equalizer in AudioLiquid Converter also has variable bandwidths on each band. The center frequency is specified in Hertz. Sound characters of the different frequencies are best discovered through experimentation. The bandwidth may be specified in octave bands. One octave band equals the frequency range of one octave on the piano keyboard. The bandwidth is the same parameter as the Q-factor found in some analog equipment. A higher Q-factor represents a narrower bandwidth. Equalizer terminology The lower part of the equalizer dialog box is used to display the filter response curve (gain versus frequency). The filter response curve is calculated mathematically and is updated as the parameters are altered.

17 Audio Processing 15 The Equalizer settings Settings Frequency response The frequency response of the current equalizer settings is visualized. Each band is visualized with a small circle with the number of the band. The currently active band is highlighted. You can activate band by clicking the circles representing each band. If you keep the mouse button down while moving the mouse cursor, you can change the gain and the center frequency of each band directly in the frequency response. Frequency Gain Bandwidth 3.6 High Frequency Rebirth Dull and lifeless recordings may be a result of lost high frequency content. By using the High Frequency Rebirth tool, you can add artificially created harmonics to brighten up the recording. Note that these are merely synthetic harmonics based on the low frequent content of the recording and this feature can only be used give the listener the impression of stronger harmonics.

18 16 AudioLiquid Converter User Guide The High Frequency Rebirth settings Settings Generate above Specifies the lower limit of the frequency band where harmonics should be synthesized. Add content / Replace content If add content is selected, the original content in the synthesis frequency band is mixed with the synthesized harmonics. If you choose replace, AudioLiquid Converter removes the original content before adding the synthesized harmonics. Dry level The amount of unprocessed signal in the output mix. High frequency level The amount of processed signal in the output mix. 3.7 Stereo Enhancer The Stereo Enhancer enhances the stereo image by filtering the left and the right differently. The filters are designed to maintain mono compatibility.

19 Audio Processing 17 The Stereo Enhancer settings Settings Stereo Depth Sets the amount of stereo enhancement from 0 (no enhancement) to 100% (maximum enhancement). 3.8 Using Audio Plug-Ins AudioLiquid Converter supports DirectX as well as VST plug-ins. Both formats have become widely used standards for audio processing plug-ins on the Windows platform. The menu Plug-Ins contains a list of the plug-ins currently installed on your computer. If you have installed a plug-in that does not appear in the list, please refresh the plug in list (see Refreshing the Plug-in List). Using DirectX or VST plug-ins is as easy as using the internal audio processing tools. You will see that previewing works exactly the same way as with the internal audio processing tools Refreshing the Plug-in List If you have installed new DirectX or VST plug-ins on your computer that do not appear in the Plug-Ins menu you should refresh the menu by selecting Plug-Ins Refresh Plug-In List. AudioLiquid Converter then rescans the plug-ins on your computer and updates the menu Specifying VST Directories VST plug-ins are not registered on your computer like DirectX plug-in, hence AudioLiquid Converter needs to know where to find them. You can specify one or more directories to scan through.

20 18 AudioLiquid Converter User Guide The VST Directories dialog lets you specify one or more VST directories to scan through. To add a new entry, click the add directory button [ ]. You can edit a directory entry by double clicking with the left mouse button. Delete an entry by clicking the delete button [ ]. 4 Creating Audio CDs AudioLiquid Converter allows you to create audio CDs containing files from your computer. The first step towards your own CD is to create a CD-Project by selecting New CD Project from the File menu. The CD Project contains a list of the audio tracks to be written on the CD and an additional toolbar for commands related to the CD Project.

21 Creating Audio CDs 19 An empty CD Project window The CD Project window contains a list of the audio tracks to be written to the audio CD. You can add existing files as a separate tracks in the track list of the CD project. 4.1 Adding an Existing Audio File You can add an existing audio file to the CD project by clicking the import audio file button ( ) or using drag and drop from the Windows Explorer. If you click the import button, a standard file open dialog box appears where you can selected the audio file or files you wish to add to the CD project. 4.2 Burning the CD When you are finished assembling your CD project, click the button labelled Burn CD from the toolbar of the CD Project window. The CD Burner dialog appears: The CD burner dialog allows you to select a CD recording device, recording speed and the number of copies. Insert a blank CD into the CD recording device. If you have several CD recording devices installed on your computer, make sure you choose the correct one from the CD Recording Device list. You can choose among different recording speeds and set the number of copies to burn. It is recommended to keep the Enable buffer protection option enabled, if supported (if not, the check box appears inactive). Click the button labelled Burn to start burning.

22 20 AudioLiquid Converter User Guide 5 Concepts of Digital Audio Before audio can be edited on computers it must be digitized. The output from most audio equipment such as tape recorders, microphones or record players is analog. Analog means that the audio signal is represented by an alternating electrical voltage. The voltage is analog to the air pressure changes in the air during the performance, hence the term analog signals. The sound card in your computer is needed to convert the constantly changing electrical voltage to a stream of numbers at fixed rate intervals. This process is done in two steps called sampling and quantization. 5.1 Sampling The conversion from a continuously changing measure to a series of measured values at discrete time instances is called sampling. The rate (or number of measurements per second) of which the sampling is done, is along with the quantization depth the most important quality factor of digital recording equipment. If it is set too low, disturbing artifacts occur. A CD quality recording is recorded with a sampling rate of samples per second. We say that the sampling frequency is Hertz (or short Hz). In fact, all frequencies above half the sampling frequency, which is known as the Nyquist frequency, are substituted by frequencies below the Nyquist frequency. This effect is called aliasing. To avoid aliasing a sampling system contains of a low pass filter which ideally filters out all frequencies above the Nyquist frequency and leaves all frequencies below unaffected. In the case of the audio CD, the highest frequency that can theoretically be recorded is Hz. 5.2 Quantization After measuring an analog input signal at fixed time intervals we have a stream of samples. The samples exist in terms of a voltage measured at a certain point in time. The voltage can usually be one of an infinite number of possible voltages within the legal voltage range. Computers cannot accurately describe every single one of the infinite number of possibilities, so it is necessary to divide the voltage range of interest into fixed sized regions. All voltages within one region are given a certain number during the quantization process. If we have a large number of regions which implies a larger number of discrete voltage levels, we can describe a voltage more accurately than with fewer voltage levels. The audio CD is quantized with voltage levels, which is the maximum number of levels possible to archive with a binary number with 16 bits. Thus we say that the Audio CD has 16 bit resolution. Modern recording studios are frequently using 24 bit resolution or even higher during the mastering process.

23 Concepts of Digital Audio 21 The digital representation of a sine wave. 5.3 The Decibel Unit (db) When the volume of the recorded sound is changed, the degree of change is usually expressed in terms of decibels or short db. This is a common unit in connection with audio. In AudioLiquid Converter, decibel is used to express the extent of change relative to the original level. Special for the decibel unit is that it is based on a logarithmic scale. Zero db represents no change, whereas an increase of six db represents a doubling of the signal amplitude. Reducing by six db results in half the signal amplitude. The decibel db versus intensity change in percent The decibel scale is chosen to suit the sensitivity curve of the human ear which have the same logarithmic property. 6 Preferences and Device Settings 6.1 Device Settings Window's multimedia system allows several different audio cards being installed at the same time. You can select which sound card to use by selecting Device Settings... from the Options menu. Choose input and output devices from the drop-down lists in the device settings dialog to change the current configuration and click the button labelled Ok.

24 22 AudioLiquid Converter User Guide Index dynamic processor Enhancement 12 -A- Equalizer high frequency rebirth Equalizer Adding Audio Files as CD Tracks Adding Processing Tools to the Batch Processing Wizard Adding source files to the Batch Processing Wizard Audio CDs 19 8 adding files as tracks creating importing audio tracks from Audio Processing adding processing tools adding source files creating folders file and sample format importing folders removing items Source Files page Target Files page target folder DDecibel (db) Device Settings Digital Audio decibel (db) quantisation sampling DirectX refreshing the plug-in list using plug-ins Dynamic Processor 15 Importing folders to the Batch Processing Wizard Introduction Requirements P- -CChannel Mixer Creating folders in the Batch Processing Wizard High Frequency Rebirth -I- -BBatch Processing Wizard -H Plug-Ins Processing tools 17 adding to the Batch Processing Wizard 8 -QQuantisation 20 -RRefreshing the DirectX plug-in list Removing items in the Batch Processing Wizard Requirements SSampling Source Files in the Batch Processing Wizard VVolume adjusting channel mixer EEffects